Method of making alkali-silico-aluminate.



A.VH. COWLES. METHOD 0F MAKING ALKALI SILIGO ALUMINATB. APPLIoAT'IoN FILED 13m-24, 1912.

Patnted J an. 5, i915.

MERECE HUTCHINSON GOWLES, 0F SEWAREN, NEW JERSEY, ASSIGNOE '1.70 THE TRIO SMELTING AND ALUMINUM COMPANY, 01? SEWAREN, NEW J Marne-n vor MAKING aLxALr-srrrco'nnmnrnarn ricerca;

Specification. of Letters Patent.

Patented dan., 5, i215,

application med December ai, 1era. serial No. recate.

new and useful Methods for Making Alkali?,

Silico-illuminate, of which the following is a Specification.

M invention relates to a method for making alkali Silico aluminate,l richer in alkali than feldspar. To carry out -my invention, l subject either in a rotary, or other form of chamber furnace, finely pulverulent clay or peta-sh feldspar, or feldspar mixed with clay or bauxite, either dryor not, to the vapors of salt and water.

l have found that the rapidity of conversion of clay into alkali-silico-aluminate in -an atmosphere of vapor of salt and vap'or 4of water or in contact with`saltand vapor 'of water isdependent upon the amount of surface that is exposed to the salt and vapory of water. rllhis conversion occurs almostI instantly when finely ground feldspar or clay, freed from uncombined water is reduced to its dust form. rllhere takes place the following reaction, which, for pure clay, is typical ,v of the process From this it will be seen that the hydro-,a l chloric acid (ll-ICI must have suiiicient water, 2ll2 and (g1/H2O) either from the admission of steam, or from the combustion gases to give the requisite amount of water in the vapors to; furnish suii'cient water for the full'reaction and to materially aid inthe condensation Vof the HC1 produced.-

'llhis quantity of water will var according to the design of the hydrochloric acid condensingsystem and amount of water that may be admitted as water to coke towers.

My process may be carried on in various types of furnace, if connectedl with 'the furnace there be a dust condensing system,

lrfthe drawings l hai'elshownone form of furnace in which my process can be carried outpand in these drawings, Figure lisa vertlcal section, and Fig. 2 a plan, partly in section of the furnace employed.

' Referring to the drawings; 1 is a furnace i body shown as formed of two truncated cones placed base to base: 2 is a dust chamber; 2L is a due pipe in which is located a suction blower A3 for conveying the gases and some' dust to the scrubber 4,5 is ther hopper through which the aluminous material and salt mixture is fed to the furnace 1; 6 is the steam inlet pipe; 7 is the inlet for the combustion gases; Sis a source of high potential electricity, 'which may be alternating or direct, connected by conductors 9 to the discharge' point l0; 11 is a mass-of coarse material and salt and 12 an atmosphere of vapor of salt; 13 is a worm, or other suitable conveyer for handling the mass 11; 14 is an acid sprinkler, for spraying acid into the scrubber l, vfor assisting the condensation of the hydrochloric acid, and 15 is a pipe leading from: the scrubber 4 to any suitable hydrochloric acid condensing system.

rlFhe operation of this form of furnace in carrying out my process is as follows: The salt mixed with the aluminous material in small masses or as a ne dry dust, prefer ably not heated high enough to drlve oil' its chemically 'combined water, is fed through the hopper 5 into the furnace. (llt is there met bythe Haine gases and vapor of water. The 'two pipes, that for the gases and the one for steam may enter the furnace chamber at practically a tangent to the inner circumference thereof, whereby a'whirl- 'I ing motion is imparted to the charge. l`he lsuction of the fan 3 draws the whirling charge up into the dust chamber, where it is electrified by the passage of electricitybetween the highly fcharged points 10, and accordingto the process set forth by Cottrell and others, the dust particles attract eachother into small masses and fall back or are' vcarried back into the furnace, the hydrochloric acid4 being sent to the acid condensing system for condensation.

lt is essential that the walls of the chamber. shall be made of material not easily fluxed by soda or potash. An aluminoua brick made from bauxite, or a brick made' from a clay containing several per mnt.

ica

j more alumina than-is in the composition of y the material that is being treated will pre- A acid away from the same can all be made of iron, as hydrochloric acid does not attack iron, unless cooled below the boiling point of the acid, so that condensation can occur.

The process can also be carried out in the ordinary type of rotary cement furnace.

Iii-this case a mixture of clay and salt in' small masses slightly agglutinated together by dampening is fed into the end of the furnace, in the proportion, say of 156 parts of clay containing about 51 parts of alumina and 112 parts of salt. This mixture is fed into the furnace with a surplus of water over and above that required to decompose the 112 parts of salt. The reaction begins as lw as the melting point of salt, and is a very rapid at `about 1800 F, .when salt vapor is formed. with rapidity. When the furnace is rotated the charge reaches the hotter zones, and the salt vapors leave the small masses of clay with which the salt is fmixed. The reaction goes on very fast due to the dust of clay forming in an atmosphereof vapor-salt and Water, and whensuch dust settles in theupper part of the furnace it again returns to the heated zone,

'.most of it passing through the same along with converted material that has entered the zone of sintering, although it is best that the material should not be melted, other than being mixed with molten salt somewhat above the zone of hottest temperature. All

materials caught in the dust chamber should either slide back, or be conveyed back into the rotating furnace. The high tension currents transmitted through the gases carrying the dust will cause precipitation of all suspended particles of salt, or other converted material, the hydrochloric acid formed being drawn away to a condensing n system by suitable means.

i When I have usedin In the rotary furnace the masses as they pass through the conversion zone should not be as large as hickory nuts, and preferably as small as peas.

this specilication the aluminate, which consists in subjectingfinely divided clay to the action of vapor of salt and water at high temperature.

2. The method of forming alkali-silicoaluminate, which consists in subjecting aluminous compounds in inely divided condition to the actionof vapor of salt and Water.

3. The method of forming alkali-silicoaluminate, which consists in preparing the aluminous material soas to expose the largest extent of surface, and subjecting `in a furnace the material thus prepared to the action of combustion gases and the vapors of salt and Water.

4. The method of producing alkali-silicoaluminate which consists in subjecting a mixture of feldspar and aluminous matcrial in finely divided condition to the action of vapor of salt and Water.

5.,A The method of forming alkali-silicoaluminate, which comprises subjecting a mixture of salt and clay in the pulverulent condition to the action of vapor of Water and furnace combustion gases.

6. The method of forming alkali-silicoaluminate and hydrochloric acid, Which comprises feeding iinely divided aluminous material and salt into a combustion furnace, precipitating the dust particles formed, con ducting the hydrochloric acid to a condensing system, and separately collecting the resulting solid product.

Signed at bewaren, in the county of Middlesex and State of New Jersey, this 10th day of December, A; 111912.

ALFRED HUTCIIINSON COWLES.

Witnesses: l

FRANK J. PHILLIPS,

ALBERT STETsoN. 

